Objective Vibrio anguillarum is an important pathogen in aquaculture, which can infect salmon, eel, perch and flounder. Rapid detection is necessary to ensure aquaculture and food safety.Methods Based on the strong affinity between V. anguillarum and its aptamers, the bacterium can capture its aptamer from the surface of colloidal gold particles and change the absorbance of the colloidal gold solution. Thus, a colorimetric method for the quantitative detection of V. anguillarum was established.Results The optical density for V. anguillarum by the present method was much higher than those of non-target bacteria such as Vibrio alginolyticus, Pseudomonas aeruginosa, Pseudomonas plecoglossicida, Aeromonas hydrophila and Edwardsiella tarda (P<0.01). The detection method had good linear relationship in the range of 1-10⁵ CFU/ml. The seawater samples with different salinities and fish body tissue samples were detected for the application, and the results showed that the recoveries and relative standard deviations of these samples were in line with the corresponding detection standards.Conclusion The present detection method has good specificity for V. anguillarum and can be used for the quantitative detection of the bacterium in aquatic products or food.